Explosives-on-a-chip smarten munitions

When U.S. military ordnance fails to detonate, allowing the enemy to escape or endangering our soldiers, the most common cause is failure in the fuze. Now the Naval Surface Warfare Center, with help from the Georgia Institute of Technology (Atlanta), has crafted a "smart" fuze using microelectromechanical systems (MEMS).

The MEMS fuze program, conceived at the Naval Surface Warfare Center, aims to create tiny explosives-on-a-chip that not only use 100x less explosives in the fuze, but also incorporate built-in arm and fail-safe mechanisms that virtually guarantee that munitions go off when they should, every time.

"Our aim is an integrated design tool able to develop a whole range of explosive precursors on different size scales," said Jason Nadler, a research engineer at the Georgia Tech Research Institute (GTRI) who is involved with the project. "Our fuzes are 'smart' in that they know the exact environment that the weapon needs to be in, and detonate it at the right time."

The MEMS fuze program plans to use semiconductor fabrication equipment to make hundreds of ultrahigh-precision detonators on a wafer at the same time. The technology is also "green," believe it or not, because the on-chip explosives use smaller amounts of toxic heavy metals and other undesirable waste products than traditional fuzes.

"This technology will enable the military to reduce the quantity of sensitive primary explosives in each weapon by at least two orders of magnitude  increasing the safety of weapon production by removing the need for handling bulk quantities of sensitive primary explosives," said Gerald Laib, senior explosives applications scientist at Indian Head and inventor of the MEMS fuze concept.

The key to the smart MEMS fuze is the integration of highly uniformed nanoscale porous copper oxide microspheres in fabric-like woven structures whose viscosity is controlled by polymer templates. After etching away the polymer, the resultant copper is laid out in micron-scale channels, each with thousands of uniformed nanoscale pores. The pores can then be filled with precise amounts of primary explosives that are detonated by an electrical signal.

Currently, the team is working on packaging the MEMS fuze in a manner that will enable it to be attached to traditional munitions, and intelligently detonated.

Also contributing to the work is Michael Beggans, a scientist in the Energetics Technology Department at Indian Head.